Fit for the roadOlder drivers' crash rates continue to drop

Today's older drivers are not only less likely to be involved in crashes than prior generations, they are less likely to be killed or seriously injured if they do crash, a new Institute study shows. That's likely because vehicles are safer and seniors are generally healthier. It's a marked shift that began to take hold in the mid-1990s and indicates that the growing ranks of aging drivers aren't making U.S. roads deadlier.

The Institute first noted the improving picture for older drivers in 2008 (see "Older drivers’ fatal crashes trend down," Dec. 27, 2008). The latest analysis bolsters the evidence that drivers 70 and older have enjoyed bigger declines in fatal crash rates per licensed driver and per vehicle miles traveled than drivers ages 35-54, referred to in the study as middle-age drivers, since 1997. A new finding is that progress appears to have slowed in recent years, with the biggest improvements in older drivers' fatal crash rates relative to middle-age drivers occurring between 1997 and 2007.

The crash outlook is improving for both older and younger drivers. During 1997-2012, fatal crash rates per licensed driver fell 42 percent for older drivers and 30 percent for middle-age ones. Looking at vehicle miles traveled, fatal crash involvement rates fell 39 percent for older drivers and 26 percent for middle-age ones from 1995 to 2008. A breakdown of the results for older drivers by age group shows that fatal crash involvement rates per licensed driver fell 36 percent for drivers ages 70-74, 46 percent for drivers 75-79 and 49 percent for drivers 80 and older during 1997-2012.

There were similar declines in older drivers' involvement rates in injury crashes that weren't fatal during the same periods.

"This should help ease fears that aging baby boomers are a safety threat. Even crashes among the oldest drivers have been on a downswing," says Anne McCartt, the Institute's senior vice president for research and a co-author of the study.

At the beginning of the study period, drivers 80 and older had by far the highest fatal crash rate, at nearly twice the rate of drivers ages 35-54 and 70-74. By 2012, the fatal crash involvement rate for drivers 80 and older improved to 1.4 times the rate of the other two age groups.

"Older drivers are not only less likely to crash in recent years, they also are sharing in the benefits of newer and safer vehicles. It also helps that older people in general are more fit than in years past, with better access to emergency services and health care," McCartt says.

These factors may be contributing to a change in travel patterns. Older drivers covered fewer miles per year on average than middle-age drivers during 1995, 2001 and 2008, data from the federal government's National Household Travel Survey show. However, older drivers increased their annual mileage by bigger percentages than middle-age drivers from 1995 to 2008. This is especially the case for drivers 75 and older, who lifted their average annual mileage by more than 50 percent from 1995 to 2008.

The fact that older drivers increased their average mileage during 1997-2012 may indicate that they are remaining physically and mentally comfortable with driving tasks. When older adults reduce their trips, there's evidence that it is often because they are self-regulating their driving in response to impairments. IIHS research has found that the more memory and physical mobility problems people develop over time, the more limits they place on their driving (see "Older drivers sense when they should limit their trips," Sept. 28, 2011).

Older drivers are not only less likely to crash than in recent years, they also are less likely to be injured or killed.

Graying population

Like many Western countries, the U.S. is seeing its population skew older. From 1997 to 2012, the population of adults 70 and older rose 19 percent. By 2050 the population of adults 70 and older is expected to reach 64 million, comprising 16 percent of the U.S. population, compared with 29 million, or 9 percent of the population, in 2012, U.S. census data indicate. The 80 and older population is expected to nearly triple to 31 million.

At the same time, an increasing number of people 70 and older are holding on to their driver licenses longer than before. The number of licensed drivers this old climbed 30 percent during 1997-2012, and the percentage of older people who were licensed edged higher from 73 to 79 percent. Licensure rates also increased more with age, from 86 to 89 percent for 70-74 year-olds, from 77 to 84 percent for 75-79 year-olds and from 55 to 68 percent for drivers 80 and older.

More than a decade ago, the Institute was among the highway safety groups initially expressing concern about the risk of having so many people 65 and older on U.S. roads (see Status Report special issue: older drivers, Sept. 8, 2001). By 2006, the predicted problem hadn't shown up in fatal crash data. A follow-up study of data through 2008 confirmed the trend (see "Older drivers’ fatal crashes trend down," Dec. 27, 2008, and "Older drivers' crash rates decline unexpectedly," June 19, 2010).

Recent trends

A total of 4,079 people ages 70 and older died in crashes in 2012. That's 31 percent fewer than in 1997, when older driver fatal crash involvements peaked in the United States.

In the new study, IIHS researchers compared trends for drivers ages 70 and older with those for drivers ages 35-54 for national fatal passenger vehicle crash involvements per 100,000 licensed drivers during 1997-2012 and per vehicle miles traveled from 1995 to 2008. Researchers used fatal crash data from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System, driver license data from the Federal Highway Administration, information on vehicle miles traveled from the highway administration's national household travel surveys and data on police-reported crashes from the National Automotive Sampling System General Estimates System and crash databases from 20 states.

"No matter how we looked at the fatal crash data for this age group — by licensed drivers or miles driven — the fatal crash involvement rates for drivers 70 and older declined, and did so at a faster pace than the rates for drivers ages 35-54," McCartt says.

More recently, the downward trend in older drivers' fatal crash involvements per licensed driver has slowed, while the declines in fatal crash involvement rates among middle-age drivers have accelerated. From 2007 to 2012, declines for older and middle-age drivers were the same at 18 percent each. This may be a byproduct of the U.S. recession, which likely affected driving patterns for middle-age people more than older people. Studies indicate that traffic fatalities fall during recessions and rise when the economy improves. That may be due to a drop in commuting, discretionary trips and alcohol-impaired driving.

Researchers also examined trends in involvement rates in nonfatal crashes of various severities per 100,000 licensed drivers during 1997-2008 between older and middle-age drivers.

The state data indicate that crash involvement rates per licensed driver for adults 70 and older also decreased in nonfatal crashes, and the declines were bigger as driver age increased. From 1997 to 2008, involvement rates in nonfatal injury crashes fell by a third for drivers 35-54, 36 percent for drivers 70-74, 38 percent for drivers 75-79 and 45 percent for drivers 80 and older. The pattern held when examining declines in property- damage-only crash involvement rates for older drivers vs. middle-age drivers.

Reduced odds of dying

Older people are generally frailer than younger adults, and this fragility makes them more vulnerable to injuries and raises their risk of dying in a crash. To gauge whether changes in relative frailty also contributed to the decline in fatal crash risk, IIHS researchers compared changes in the odds of death or serious injury among older and middle-age crash-involved drivers using the state crash data.

During 1997-2008, the odds that crash-involved drivers age 35-54 or 70 and older sustained a fatal injury declined, and the decrease was significantly larger for older drivers than for middle-age drivers. In 1997, drivers 70 and older were 3.5 times as likely to die in a crash as drivers ages 35-54, and drivers 80 and older were 5.4 times as likely to die in a crash as middle-age drivers. By 2008, drivers 70 and older were 3.2 times as likely to die in a crash as drivers 35-54, and drivers 80 and older were 4.3 times as likely to die in a crash as middle-age drivers.